body { 
    display: grid;
    grid-template-areas: 
      "header header header header"
      "nav article article2 ads"
      "footer footer footer footer";
    grid-template-rows: 60px 1fr 300px 40px;  
    grid-template-columns: 20% 1fr 20%;
    grid-row-gap: 10px;
    grid-column-gap: 10px;
    height: 100vh;
    margin: 0;
    } 
    header, footer, article,nav, div {
      padding: 1.2em;
      }
    #pageHeader {
      grid-area: header;
      }
    #pageFooter {
      grid-area: footer;
      }
    #mainArticle { 
      grid-area: article; 
      background-color: rgb(226, 226, 226) ; 
      display: flex;
      flex-wrap:nowrap ;  
      
      }
    #mainArticle { 
        grid-area: article; 
        background-color: rgb(226, 226, 226) ; 
      }
    #mainNav { 
      grid-area: nav; 
      display: flex;
      flex-direction: column;
      }
    #siteAds { 
      grid-area: ads; 
      display: flex;
      flex-direction:row ;
      } 
      .ia{
        display: inline-block;
        width: 70px;
        height: 20px;
        text-decoration:none;
        color: rgb(8, 0, 0);
    }
    .iaa{
        display: inline-block;
        width: 180px;
        height:20px;
        text-decoration:none;
        color: rgb(8, 0, 0);
    }
    a{
      display: inline-block;
      text-decoration:none;
      color: rgb(8, 0, 0);
    }
    button{
      width: 100px; /* 宽度 */
      height: 40px; /* 高度 */
      border-width: 0px; /* 边框宽度 */
      border-radius: 3px; /* 边框半径 */
      background: #11181f; /* 背景颜色 */
      cursor: pointer; /* 鼠标移入按钮范围时出现手势 */
      outline: none; /* 不显示轮廓线 */
      font-family: Microsoft YaHei; /* 设置字体 */
      color: white; /* 字体颜色 */
      font-size: 17px; /* 字体大小 */
    }
    button:hover{
      background: #5599FF;
    }


    /* 下拉菜单 */
  /* 设置下拉按钮的样式 */
.dropbtn {
  background-color: #4CAF50;
  color: white;
  padding: 16px;
  font-size: 16px;
  border: none;
  cursor: pointer;
}

/* 容器 <div> - 需要放置下拉内容 */
.dropdown {
  position: relative;
  display: inline-block;
}

/* 下拉内容（默认隐藏） */
.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}

/* 下拉链接 */
.dropdown-content a {
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
}

/* 悬停时更改下拉链接的颜色 */
.dropdown-content a:hover {background-color: #f1f1f1}

/* 悬停时显示下拉菜单 */
.dropdown:hover .dropdown-content {
  display: block;
}

/* 显示下拉内容时，更改下拉按钮的背景颜色 */
.dropdown:hover .dropbtn {
  background-color: #3e8e41;
}
.lunbo{
  width: 280px;
}